Spiral inductor

Abstract

The present invention relates to a spiral inductor for use in a semiconductor device. The spiral inductor comprises a dielectric layer formed of a plurality of layers stacked on a semiconductor substrate, and a plurality of curved metal lines formed in the dielectric layers which are serially connected in order to form a circular spiral shape.

1. A spiral inductor comprising:
 a dielectric layer formed of a plurality of layers stacked on a semiconductor substrate; and 
 a plurality of curved metal lines disposed in the dielectric layer which are serially connected in order to form a circular spiral shape; and 
 wherein the metal line disposed at the center portion of the circular spiral shape has a first height and the metal line disposed at the outer portion of the circular spiral shape has a second height. 
 
   
   
     2. The spiral inductor according to  claim 1 , wherein the metal lines of the circular spiral shape have a width which gradually narrows from a first width in the metal lines of the outer portion of the circular spiral shape to a second width in the metal lines of on a center portion of the circular spiral shape. 
   
   
     3. The spiral inductor according to  claim 1 , wherein a gap is formed between the plurality of the metal lines, wherein the distance between the plurality of metal lines is constant. 
   
   
     4. The spiral inductor according to  claim 1 , wherein the first height of the metal line disposed at the center portion of the spiral is higher than the second height of the metal line disposed at the outer portion of the spiral shape, such that the metal lines form a spiral with a conical shape. 
   
   
     5. The spiral inductor according to  claim 1 , wherein the first height of the metal line disposed at the center portion of the circular is lower than the second height of the metal line disposed at the outer portion of the spiral shape, so that the metal lines form a spiral with an inverted conical shape. 
   
   
     6. The spiral inductor according to  claim 1 , wherein the thicknesses of the metal lines gradually increase from a first thickness in the metal lines of the outer portion of the circular spiral shape to a second thickness in the metal lines of the center portion of the circular spiral shape. 
   
   
     7. The spiral inductor according to  claim 1 , wherein the thicknesses of the metal lines are gradually reduced from a first thickness in the metal lines of the outer portion of the circular spiral shape to a second thickness in the metal lines of the center portion of the circular spiral shape. 
   
   
     8. The spiral inductor according to  claim 1 , further comprising a first connecting terminal connected to an end of the metal line disposed at a center portion of the circular spiral shape; and a second connecting terminal connected to another end of the metal line disposed at an outer portion of the circular spiral shape. 
   
   
     9. The spiral inductor according to  claim 8 , further comprising at least one dielectric layer placed between the metal line of the center portion of the circular spiral shape connected to the first connecting terminal and other metal lines of the circular spiral shape. 
   
   
     10. The spiral inductor according to  claim 8 , wherein the plurality of metal lines are interconnected at an area where the plurality of metal lines overlap with the first connecting terminal, as viewed from the top the semiconductor substrate. 
   
   
     11. The spiral inductor according to  claim 1 , further comprising a dielectric layer disposed between the bottom layer metal line of the plurality of metal lines and the semiconductor substrate. 
   
   
     12. The spiral inductor according to  claim 11 , wherein the thickness of the dielectric layer is 1 μm or more. 
   
   
     13. A spiral inductor comprising:
 a dielectric layer formed of a plurality of layers stacked on a semiconductor substrate; 
 a plurality of curved metal lines disposed in the dielectric layer which are serially connected in order to form a circular spiral shape; 
 a first connecting terminal connected to an end of the metal line disposed at a center portion of the circular spiral shape; and 
 a second connecting terminal connected to another end of the metal line disposed at an outer portion of the circular spiral shape; 
 wherein the curved metal line disposed at the center portion of the circular spiral shape has a first height and the curved metal line disposed at the outer portion of the circular spiral shape has a second height. 
 
   
   
     14. The spiral inductor according to  claim 13 , wherein the thickness of the dielectric layer is 1 μm or more. 
   
   
     15. The spiral inductor according to  claim 13 , wherein the metal lines of the circular spiral shape have a width which gradually narrows from a first width in the metal lines of the outer portion of the circular spiral shape to a second width in the metal lines of on a center portion of the circular spiral shape. 
   
   
     16. The spiral inductor according to  claim 13 , wherein the first height of the metal line disposed at the center portion of the spiral is higher than the second height of the metal line disposed at the outer portion of the spiral shape, such that the metal lines form a spiral with a conical shape. 
   
   
     17. The spiral inductor according to  claim 13 , wherein the first height of the metal line disposed at the center portion of the circular is lower than the second height of the metal line disposed at the outer portion of the spiral shape, so that the metal lines form a spiral with an inverted conical shape. 
   
   
     18. The spiral inductor according to  claim 13 , wherein the thicknesses of the metal lines gradually increase from a first thickness in the metal lines of the outer portion of the circular spiral shape to a second thickness in the metal lines of the center portion of the circular spiral shape. 
   
   
     19. The spiral inductor according to  claim 13 , wherein the thicknesses of the metal lines are gradually reduced from a first thickness in the metal lines of the outer portion of the circular spiral shape to a second thickness in the metal lines of the center portion of the circular spiral shape. 
   
   
     20. The spiral inductor according to  claim 13 , further comprising at least one dielectric layer placed between the metal line of the center portion of the circular spiral shape connected to the first connecting terminal and other metal lines of the circular spiral shape. 
   
   
     21. The spiral inductor according to  claim 13 , wherein the plurality of metal lines are interconnected at an area where the plurality of metal lines overlap with the first connecting terminal, as viewed from the top the semiconductor substrate. 
   
   
     22. The spiral inductor according to  claim 13 , wherein a gap is formed between the plurality of the metal lines, wherein the distance between the plurality of metal lines is constant. 
   
   
     23. The spiral inductor according to  claim 13 , further comprising a dielectric layer disposed between the bottom layer metal line of the plurality of metal lines and the semiconductor substrate. 
   
   
     24. A spiral inductor comprising:
 a dielectric layer formed of a plurality of layers stacked on a semiconductor substrate; and 
 a plurality of curved metal lines disposed in the dielectric layer which are serially connected in order to form a circular spiral shape; and 
 wherein the thicknesses of the metal lines gradually increase from a first thickness in the metal lines of an outer portion of the circular spiral shape to a second thickness in the metal lines of a center portion of the circular spiral shape. 
 
   
   
     25. A spiral inductor comprising:
 a dielectric layer formed of a plurality of layers stacked on a semiconductor substrate; and 
 a plurality of curved metal lines disposed in the dielectric layer which are serially connected in order to form a circular spiral shape; and 
 wherein the thicknesses of the metal lines are gradually reduced from a first thickness in the metal lines of an outer portion of the circular spiral shape to a second thickness in the metal lines of a center portion of the circular spiral shape.